Optical touch device

Abstract

An optical touch device is presented. When the optical touch device is in a sleep mode, only one of all image sensors of the optical touch device is enabled to detect an indication object on a touch area, so as to determine a wakeup time of the entire optical touch device.

1 . An optical touch device, applied to provide a touch area, comprising:
 at least one image sensor; and   a processing unit, electrically connected with the image sensor;   wherein when the optical touch device is in a sleep mode, one of the image sensors that present the sleep mode is enabled, such that the enabled image sensor detects an indication object on the touch area; and   when the image sensor detects that the indication object exists on the touch area, the image sensor notifies the processing unit to wake up the entire optical touch device.   
     
     
         2 . The optical touch device according to  claim 1 , wherein when the optical touch device is in the sleep mode, the enabled image sensor detects the indication object with a first frequency that is lower than a detection frequency when the image sensor is in a normal operation mode. 
     
     
         3 . The optical touch device according to  claim 1 , further comprising a timer, wherein when the optical touch device is in the sleep mode, the timer is used to periodically enable the image sensor in the image sensors, such that the enabled image sensor detects the indication object on the touch area, so as to determine a wakeup time the optical touch device. 
     
     
         4 . The optical touch device according to  claim 3 , wherein the timer is disposed in the image sensor enabled by the timer. 
     
     
         5 . The optical touch device according to  claim 3 , wherein the timer is disposed outside the image sensor enabled by the timer. 
     
     
         6 . The optical touch device according to  claim 1 , wherein when the image sensor detects that the indicating sensor exists on the touch area, the image sensor sends a signal excluding coordinate information of the indication object to the processing unit, such that the processing unit wakes up the entire optical touch device according to the signal. 
     
     
         7 . The optical touch device according to  claim 6 , wherein the image sensor has an interception pin, electrically connected to the processing unit, and for transmitting the signal. 
     
     
         8 . The optical touch device according to  claim 1 , wherein the image sensor notifies the processing unit with serial transmission. 
     
     
         9 . The optical touch device according to  claim 8 , wherein the image sensor notifies the processing unit through an Inter-Integrated Circuit (I2C) bus. 
     
     
         10 . The optical touch device according to  claim 1 , wherein when the optical touch device is in the sleep mode, the enabled image sensor detects a local area of the touch area, to determine whether the indication object exists on the touch area. 
     
     
         11 . The optical touch device according to  claim 1 , further comprising:
 at least one light-emitting element;   wherein each image sensor is corresponding to one of the light-emitting elements, and when the optical touch device is in the sleep mode, an image sensor and an corresponding light-emitting element are enabled simultaneously, such that the enabled image sensor detects the indication object on the touch area according to light emitted by the corresponding light-emitting element.   
     
     
         12 . An optical touch device, comprising:
 at least one light-emitting element, at least one image sensor, and a processing unit, wherein each image sensor is corresponding to one of the light-emitting elements, the processing unit is connected with these image sensors, the optical touch device further comprises a timer, and when the optical touch device is in a sleep mode, the timer is used to periodically actuate one of the image sensors, such that the enabled image sensor detects an indication object on a touch area to determine a wakeup time of the optical touch device.   
     
     
         13 . The optical touch device according to  claim 12 , wherein the image sensor has an interception pin, and the interception pin is electrically connected to the processing unit, when the optical touch device is in the sleep mode, and the image sensor detects that the indication object exists on the touch area, the image sensor sends an interception signal to the processing unit through the interception pin, such that the processing unit wakes up the entire optical touch device according to the interception signal.